The sources spoke days after CNBC parent Comcast launched a $65 billion cash bid for the assets, which include Fox's movie studios, networks National Geographic and FX, Star TV, stakes in Sky, Endemol Shine Group and Hulu as well as regional sports networks. Comcast's bid was a 19 percent premium to Disney's offer.
Earlier, Disney reached an agreement with Fox to buy the assets for $52.4 billion in stock, and that bid has gained in value to about $55.5 billion.CNBC has reported the company was willing to add cash if needed to win the bidding.
Fox's board meets Wednesday to discuss Comcast's bid, and would engage in talks if it deems the offer superior. If that happens, Disney has five days to match Comcast's offer.
Disney shares closed down 1.6 percent on Monday, Comcast was down 3.8 percent and Fox was down 0.4 percent.
Earlier Monday, Pivotal Research Group downgraded Disney shares to a sell rating, saying it is boxed into a corner on the bidding, and a higher deal price would reduce the value of Disney to its shareholders. On the flip side, losing the deal would also be a negative because Disney wouldn't be able to realize the savings it wants to produce from the transaction, the research firm wrote.
Comcast's bid came a day after a federal judge cleared the way for AT&T's acquisition of Time Warner, a deal the government had tried to block on competitive grounds. The decision was expected to set off a new wave of big company mergers.
The Fox assets would boost Comcast's presence internationally and shore up its entertainment units at a time when consumers are shunning traditional cable operators in favor of internet-based video streaming such as Netflix.
Comcast had gone after the Fox properties before, but Fox, controlled by the Murdoch family, chose Disney. In launching the bid last week, Comcast CEO Brian Roberts said in a letter to Fox's board, "We were disappointed when [Fox] decided to enter into a transaction with The Walt Disney Company, even though we had offered a meaningfully higher price." He added, "We are pleased to present a new, all-cash proposal that fully addresses the Board's stated concerns with our prior proposal."
Disclosure: Comcast is the parent company of NBCUniversal and CNBC.
Allergan has completed its strategic review and will sell its women's health and infectious disease businesses, sources told CNBC.
The drugmaker announced the review earlier this year, but Brent Saunders, its chief executive, has said he was opposed to fundamental changes to its business strategy. Still, the review considered options such as splitting up the company, selling assets, making acquisitions and using capital to buy back shares.
Saunders is scheduled to make a presentation at the Bernstein Strategic Decisions investor conference in New York on Wednesday morning.
Allergan, the maker of Botox, is trying to right itself after a difficult year. Its shares are down 32 percent over the last 12 months and fell nearly 2 percent in trading on Tuesday. They dropped more than 1 percent in early trading Wednesday.
The sale of the units would allow Allergan to refocus on four key areas, including medical aesthetics and dermatology, eye care, central nervous system and gastrointestinal. Proceeds from the sales could be used to pay down debt and buy back shares.
A recent note from Cowen analysts valued the women's health business at $4 billion and the infectious disease business at $2 billion. The units could attract private equity buyers, previous reports have said.
David Tepper's Appaloosa Management recently got Federal Trade Commission approval to take an activist stance using his 3.7 million shares of Allergan.
— CNBC's Liz Moyer contributed reporting.
Xerox and Fujifilm Holdings are in "active talks" to renegotiate a deal the two struck in January, according to remarks by their lawyers at a court hearing Thursday.
The $6.1 billion deal, which would combine Xerox into an existing joint venture with Fuji, drew opposition from prominent shareholders such as Darwin Deason, Xerox's largest individual shareholder, who sued in New York state court saying the deal undervalues the American copier and printing company.
Deason and fellow activist investor Carl Icahn have been fighting the deal, saying it unfairly favors Fuji.
But while the lawyers said in court that the two sides were in talks, it wasn't clear that they were going to be able to reach a new deal.